Lonsk was formerly part of the German Empire. In the German Empire, the place was called Lenzwiesen.
The place is now called Łążek and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Lonsk | German Empire | Schwetz | before the Versailles Treaty |
| Łążek | Poland | Świecie | after the Versailles Treaty |
| Lenzwiesen | German Empire | Schwetz (Weichsel) | 1939 |
| Łążek | Poland | Świecie | 1945 |
| Łążek | Poland | Bydgoszcz | 1992 |